The following projects will be carried out to investigate the mechanism of proton transport and energy conservation in the mitochondrial inner membrane: 1. Measurement of the membrane potential in large mitochondria with a treated glass microelectrode. 2. Correction of measured P/O ratios for proton leaks to give the theoretical maximum efficiency of oxidative phosphorylation. This number is about 2 to 2.5 with NADH and 1.3-1.5 with succinate. 3. Study of the rapid kinetics of redox reactions in cytochrome oxidase.